This Application relates generally to surgical stapling procedures and instruments, and more particularly relates to improvement in devices mounted on the stapler to reinforce the staple line, especially beneficial in endoscopic procedures.
When staples are applied to fragile tissue, particularly fragile emphysematous lung in the course of lung volume reduction surgery, there is a very real danger of tearing of the tissue with consequent leaking of air. When this happens the patient is put at serious risk of a prolonged hospitalization, potential reoperation and even mortality. The solution to this problem has been to use a strip of material mounted on the anvil and the cartridge arms of the stapler so that when the staples are fired the tissue is compressed between two layers of material that is itself much stronger than the lung tissue. The material must be thin enough for the staples to close over the sandwich of membrane and compressed tissue, strong enough for there to be no risk that staples could possibly tear through it and biocompatible so that it may be left in the body without producing excessive host reactions. The material most used has been tanned bovine pericardium, but permanent or slowly absorbable synthetic materials with proven effectiveness as patch materials in other parts of the body such as extruded polytetrafluorethylene, polyester, polypropylene, vicryl, dexon can all be used provided they are thin enough and strong enough.
The bolster material may be hand cut and tied to the stapler arms. It is far more conveniently supplied sterile, precut, and with a mounting mechanism that enables it to be easily placed on the stapler, and remain secure there while the stapler is maneuvered onto the tissue. For endoscopic use in which the stapler is passed through the body wall, the mounted bolster must not be displaced during this maneuver. Ideally, the removal of the mounting mechanism must be easily and routinely accomplished with a minimum of maneuvers and time. A currently available product as described in U.S. Pat. No. 5,503,638 has pericardium attached by sutures to a rectangular polyethylene three sided box that fits over the staple arm. For removal the sutures need to be cut at least twice and sometimes four times for release of the mounting mechanism. Access to the sutures may require twisting or rotating the stapler from side to side. In endoscopic use, particularly, the torque thereby applied to the delicate adjacent lung tissue outside the staple line may cause tears to occur so that the beneficial effect of the bolstering of the staples is lost. After the removal of the sutures, the polyethylene "box" must also be removed. These and other disadvantages are eliminated by bolster mounting assemblies in accordance with the present invention.